1. Field of the Invention
The present invention relates to a parallel processor for efficient processing of mobile multimedia, and more particularly, to a parallel processor structure for efficiently using various multimedia-related standard technologies, such as 3-dimensional (3D) graphics, moving-picture codecs including H.264/H.263/Moving Picture Experts Group (MPEG)-4, still-image codecs including Joint Photographic Experts Group (JPEG) and JPEG 2000, and audio codecs including MPEG-1 Audio Layer 3 (MP3).
The present invention is derived from a project entitled “Components/Module Technology for Ubiquitous Terminals [2006-S-006-02]” conducted as an IT R&D program for the Ministry of Information and Communication (Republic of Korea).
2. Discussion of Related Art
The necessity for various portable devices, such as a cellular phone, a Personal Digital Assistant (PDA), a Portable Multimedia Player (PMP), etc., to provide various media services, such as moving pictures, still images, audio, 3D graphics, etc., is on the increase. Thus far, to implement such multimedia terminals, service modules for respective media, such as moving pictures, still images, audio, 3D graphics, etc., have been developed using software, hardware, or both, and the developed service modules have been installed in a terminal according to a service type that the terminal will provide.
Although a general microprocessor installed in a portable terminal has lower performance than that of a general personal computer (PC), it has to perform a variety of tasks. Thus, when real-time execution is needed, the developed service modules are implemented by hardware or hardware-software integrated design. In other words, exclusive hardware is generally used for real-time execution in the service module. To provide real-time service for various media to one portable terminal, exclusive hardware for the respective media must be installed in the terminal. Such an increase in hardware leads to increases in power consumption as well as cost, and the increase in power consumption reduces efficiency of the portable terminal.
Instead of the method using exclusive hardware for respective media services, a method using a parallel processor can be employed, which provides all kinds of media services using one parallel processor. For example, when a moving picture service is performed, an algorithm for a moving picture medium is executed in the parallel processor, and when a 3D graphics service is performed, algorithms for geometric transformation or rasterization are performed in the parallel processor. Therefore, the method using a parallel processor has advantages of low cost, low power consumption, flexibility and high performance, in comparison with the method using exclusive hardware for respective media.
Much research on parallel processors has been conducted.
A parallel processor “MorphoSys” was researched at the University of California, Irvine to perform multimedia computation. MorphoSys can control processors within the parallel processor in units of a row or column. Therefore, operation of the processors can be differently controlled according to rows or columns. Using such a structure, it is possible to develop a more flexible parallel algorithm compared to a parallel processor structure in which all processors perform the same operation. However, in order to control rows or columns differently, different control signals for respective rows or columns must be generated. In other words, as many control signals as the number of rows or columns must be generated, and thus a control signal bus having a width capable of supporting the control signals must be connected to the parallel processor. Such an increase in bus width leads to increases in hardware cost and power consumption.
Among multimedia computing, 3D graphics needs a floating-point operation, thus requiring a very large amount of computing. A parallel processor “Kestrel” performed the floating-point operation at the University of California, Santa Cruz, which took a long time. Since the floating-point operation takes a long time without an exclusive device for the floating-point operation, exclusive hardware is generally used to perform the floating-point operation. Also in a processor “T4G” of Toshiba, an exclusive module for rendering is used for processing 3D graphics. When an exclusive module is used like this, high-speed computing is enabled, but cost increases.